[srinath]

Hello

i am trying to model supersonic flow over a ramp.
These are my bc's and domain.


Inlet--supersonic inlet (P,U,T) specified.

Outlet--Extrapolated outlet (dp/dn,du/dn.dT/dn=0),
since flow at outlet is supersonic.

top of channel--symmetry(to simulate an infinite domain).

bottom of channel before ramp--symmetry.

ramp--slip.

When i run the case with these bc's, the solution blows up.
I would appreciate it if someone tell me what i am doing wrong

Regards
Srinath

[srinath]

Solved it, was using wrong values of R and Cv

[varun]

Hi Srinath

I used the same conditions and could not solve the problem - the solutiuon blew up. I used U = 2, p = 1, T = 1, Cv = 1.785, R = 0.714. What values didi you use?

How far above the ramp did u put you rfarfiedl condition?

Regards
Varun

[srinath]

Hi Vikas

I converted everything to SI, since otherwise comparison won't be correct. R=.714,Cv=1.785 does not correspond to air, for which we have test results.
Domain is exactly as on the nasa webpage
http://www.lerc.nasa.gov/WWW/wind/va...dge/wedge.html
with symmetry bc at top of domain.

I used R=287(for air), then get Cv(assume gamma=1.4), then a, then U = 2.5*a
similarly convert P,T etc in NASA problem to SI

Note that i ran it for Mach no=2.5(not 2.0), Angle was underpredicted by about 5 degrees.

Regards
Srinath